Apparatuses of this type are used in particular for the casting of steel into a tundish or a similar container. By means of a manipulator acting on the support ring the casting tube is pressed against the pouring sleeve of the sliding closure. In this way a metal-tight connection is established between the two parts. At the same time both parts are centred axially relative to one another so that a casting channel passing through both parts in operation is produced.
With this type of casting tube mounting there is disposed in the support ring of the casting tube a resilient centring ring the conical centring surface of which interacts with a receiving bore hole in the sliding closure which is also conical. By means of the resilient arrangement any dimensional deviations of the fireproof parts or unevennesses in the receiving bore hole, for example due to splashes of metal or other contaminating items, are compensated. However, it is a disadvantage with the resilient arrangement that it does not always guarantee correct alignment of the casting tube.